The present invention relates generally to limit gauges that measure workpiece thicknesses and more particularly to limit gauges that are disposed on machines to measure workpieces that are to be planed by the machines.
Gauges that indicate the setting of a machine for planing a workpiece, such as a board, to a desired thickness are known in the art. Such gauges are commonly mounted on an external or at least visible surface of planing machines. These gauges usually indicate the height of planing blades within the machine and thus the thickness of a workpiece only after it has been planed. One could use this gauge to determine the preplaned thickness of a workpiece by inserting the workpiece beneath the blades, lowering the latter until they make contact with the upper surface of the workpiece, and reading the gauge. Of course, the gauges have not been designed for this purpose and would obviously be far less efficient than would simpler means such as hand-held scales or calipers.
An object of the present invention is to provide a limit gauge that is mountable on a planing machine and that provides means for quickly, easily and conveniently measuring the thicknesses of workpieces such as boards.
Another object is to provide a limit gauge that requires minimal, if any, material in addition to that required to fabricate a machine on which it is disposed.
A further object is to provide a limit gauge that is an integral part of an element of the combination of the machine.
Yet another object is to provide a limit guide having permanently sized notches that indicate a plurality of set maximum material thicknesses and a slidable member for indicating intermediate thicknesses.
A feature of the present invention is that the limit gauge is molded as an integral part of the combination of the elements of the machine.
Another feature is that the generally horizontal surfaces of the limit gauge over which workpieces are slid are convexly curved.
Still another feature is that indications of sizes of individual measuring notches are located proximate each respective notch.
A feature of another preferred embodiment of the limit gauge is that a slidable member is slidably disposed on the limit gauge such that jaws thereof extend into respective notches to effectively vary their dimensions when the slidable member position is shifted along the limit gauge.
A feature of still another preferred embodiment of the limit gauge is that it is readily separable from the planing machine, thus allowing the former to be used to measure workpieces at a distance from the latter.
An advantage of the present invention results from the fact that, since the limit gauge is molded as an integral part of a molded top of the machine, and a top is required anyway, little if any additional material is required to include the limit gauge and no machining costs are incurred in the gauge""s fabrication.
An additional advantage is that the convexly curved surfaces of the limit gauge minimize the areas of contact between workpieces and the surfaces, thus facilitating the sliding of workpieces over the surfaces.
Another advantage is that one preferred embodiment of the limit gauge has no moving parts and requires no adjusting.
Still another advantage is that the limit gauge position and configuration make the limit gauge always readily available and easy to use.
Yet another advantage is that one preferred embodiment of the limit gauge includes a notch the longitudinal dimension of which is adjustable.
Another advantage is that one preferred embodiment of the limit gauge is separable from the planing machine, allowing manual measurement of workpieces without having to bring an unwieldy workpiece to the limit gauge.
In realizing the aforementioned and other objects, features and advantages, the limit gauge of the present invention includes an elongate body extending in a longitudinal direction. The body has at least one elongate ridge extending longitudinally along the top thereof. A plurality of laterally extending notches are defined in an upper portion of the at least one ridge. Each notch has a mutually different but uniform longitudinal dimension to facilitate measuring a workpiece thickness by attempting to slide, and sliding, the workpiece through adjacent notches.
The bottom surface of each of the plurality of notches is convexly curved in a lateral direction to facilitate the free passage of workpieces of appropriate thicknesses through the notches. The lands between adjacent notches of the plurality of notches are also convexly curved in a lateral direction to facilitate sliding workpieces toward a selected notch.
The limit gauge is preferably formed of structural foam, and the body is also formed as a top in a housing for a planing machine. The longitudinal dimension of each of the plurality of notches is indicated by characters disposed proximate each respective notch.